It has previously been proposed in U. S. Pat. No. 3,151,908 issued to Horst on Oct. 6, 1964 to combine a pickup truck having a cargo bed defined by the cab, side and back walls with a top that can rest on the upper edge of the side walls as a cover for the cargo bed or be elevated by posts to provide space for a camper which can be closed by curtains on the sides and rear. The lower ends of the posts fit into sockets in the side walls. This proposal has not been accepted by the public, probably because of the bother of fastening the posts to the top when it is to be used in elevated position and the poor weatherproofing provided by curtains.
A further prior proposal in U. S. Pat. No. 3,367,347 issued to Smith on Feb. 6, 1968, is to combine a pickup truck bed with a cover that can be converted into a tent. It suffers from much the same inadequacies as Horst.
Another prior proposal in U. S. Pat. No. 3,458,232 issued to Frank on July 29, 1969, is to combine a pickup truck bed with a plurality of hinged and pivoted panels to construct a box-like enclosure above the side and end walls of the bed. There has been no substantial public acceptance of this proposal, probably because the parts take up so much room in the bed of the truck that it must be used either as a camper or truck but not a true combination vehicle.
Still a further proposal in U. S. Pat. No. 3,649,073 issued to Whitmore on Mar. 14, 1972, is to provide a cover for the bed of a pickup truck which can be raised from a lower position on top of the side and rear walls of the bed to an upper position but this leaves the sides and ends open. It is unsuitable for a camper.
Other similar proposals with modifications in the means for lifting the cover from its lower to upper positions, or for supporting a fabric cover, have been made, all of which are evidence of a long felt but unfulfilled need for a truly combined pickup truck and built-in camper which does not detract significantly from the carrying capacity of the truck and which can convert it into a true camper without bother.